The document has become corrupt. If you cannot reassemble the document from its original sources and no version of the file is available from a back up, then you can try to print the pdf file to the virtual Acrobat Printer to create a new version of the file. This won't be of the same quality as the original, but it might be acceptable.

I received the same "This document's page tree contains an invalid node." error. I saved as to a different location on my hard drive using the same file name and Acrobat didn't have a problem anymore just using the new file. The error would initiate when I used Foxit Editor to delete some pages of a pdf.

I do not understand why Adobe PDFs are so flakey. I produce a weekly newsletter at work.

To make it searchable I PDF it using Adobe Acrobat X Pro and insert it into a PDF for the 2013 issues. Apart from inserting each issue I create a bookmark and set destination. That is all I do and yet the PDFs keep corrupting. I keep getting the message "The document's page tree contains an invalid node". ( I view it with Adobe Reader X). In desperation I created a new PDF and populated it with the weekly issues. This worked for a little while, but now the error has come up again. Is no one in the Adobe technical side looking to see what is causing this bug?